Scattering studies of the size and structure of cellulose dissolved in aqueous hydroxide base solvents

Beatrice Swensson; Sebastian Lages; Barbara Berke; Anette Larsson; Merima Hasani

doi:10.1016/j.carbpol.2021.118634

Scattering studies of the size and structure of cellulose dissolved in aqueous hydroxide base solvents

Carbohydr Polym. 2021 Nov 15:274:118634. doi: 10.1016/j.carbpol.2021.118634. Epub 2021 Sep 4.

Authors

Beatrice Swensson¹, Sebastian Lages², Barbara Berke³, Anette Larsson⁴, Merima Hasani⁵

Affiliations

¹ Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden. Electronic address: beatrice.swensson@chalmers.se.
² Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden. Electronic address: lages@chalmers.se.
³ Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden. Electronic address: barbara.berke@chalmers.se.
⁴ Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden; Wallenberg Wood Science Center, The Royal Institute of Technology, SE-100 44, Stockholm, Sweden. Electronic address: anette.larsson@chalmers.se.
⁵ Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden; Wallenberg Wood Science Center, The Royal Institute of Technology, SE-100 44, Stockholm, Sweden. Electronic address: merima.hasani@chalmers.se.

PMID: 34702457
DOI: 10.1016/j.carbpol.2021.118634

Abstract

Combining NaOH with other hydroxide bases with superior dissolution properties can be a means of improving dissolution of cellulose. However, this raises questions about how the size and structure of cellulose vary when dissolved in different hydroxide bases. Here, cellulose in aqueous solutions of NaOH, Tetramethylammonium hydroxide (TMAH), Benzyltrimethylammonium hydroxide (Triton B) and previously studied equimolar solutions of NaOH/TMAH and NaOH/Triton B were investigated using small angle X-ray scattering, static and dynamic light scattering. The results show that cellulose in NaOH(aq) is largely aggregated and that the more hydrophobic TMAH and Triton are capable of molecularly dissolving cellulose into worm-like conformations, stiffer than in NaOH. The dissolution properties of mixtures are highly dependent on the compatibility of the individual bases; in line with previous observations of the properties of the solutions which now could be correlated to the structure of the cellulose on a nano- and microscale.

Keywords: Cellulose; DLS; Dissolution; Hydroxide; SAXS; SLS.